Constant velocity joints are used in numerous vehicular applications where the rotational velocity oscillation of a conventional cardan joint is unacceptable. For example, in the front suspension of a front wheel drive automobile, there will be two constant velocity joints per axle. They are also used in off-road heavy-duty equipment, in trucks, and in high performance recreation vehicles.
When the application is not overly environmentally adverse, constant velocity joints are excellent. However, in environmentally unfriendly applications they are less desirable because of the problems of keeping dirt and debris out of the joint. A better understanding of that will be appreciated upon review of FIG. 1 which shows a prior art constant velocity joint.
In the normal automotive environment a seal of this type can protect the joint for many thousands of miles of operation. It is not, like in conventional cardan joints, a simple secondary dust shield, but is the primary seal for keeping foreign material out of the workings of the joint mechanism. Thus, when the seal fails, it is not long thereafter, without attention, that the joint will fail.
It is desirable to use constant velocity joints in more environmentally demanding applications, and the ability of the seal to withstand tough environmental conditions is a strong factor. In off the road applications, for example, rocks and debris thrown up by the tires, or over which the vehicle can skid are readily available to damage the seal.
For other recreational applications, such as four wheel drive vehicles, all-terrain vehicles, rock climbers, and the like where the universal joints are flexed to their limits because of the uneven nature of the terrain, the constant velocity joints will also be a benefit. But again, there is also the possibility of wearing the seal with almost certain failure of the joint to follow, particularly when running through sand, water, and the like.
What will be shown and described herein are various novel and nonobvious improvements to seals for universal joints.